Two sneaker companies are at war over this shoe from the '60s

The runaway success of the Adidas Stan Smith has spawned multiple copycats — but one in particular has really gotten under the German brand's skin.

Adidas has filed a lawsuit against sportswear manufacturer Skechers for its "unlawful behavior" and alleged copycat designs, namely the Stan Smith shoe, which is a dead ringer for the Onix sneaker by Skechers.

The Onix apes the 1963 shoe made famous by tennis star Stan Smith with its green markings, perforations, and general shape.

Adidas said in a statement that it "will not stand silently while Skechers copies the iconic Stan Smith shoe and uses terms like 'Adidas Originals' and 'Stan Smith' as keywords on its website to divert customers looking for authentic Adidas shoes."

At the time of this writing, a search on the Skechers website for "Stan Smith" yielded a link to the Onix shoe.

After saying that Adidas doesn't "appreciate" how its designs are routinely "knocked off around the globe," he noted that all designers tend to be copycats. "If there are things that look and feel similar, I don't see that as any kind of threat," he said.

A spokesperson for Skechers told Business Insider the company does not comment on pending litigation.

A public relations representative for Adidas shared the following statement:

"Adidas filed a lawsuit today against Skechers to protect its valuable intellectual property and put an end to a long-term pattern of unlawful conduct by Skechers to sell shoes that infringe Adidas' rights. Adidas will not stand silently while Skechers copies the iconic Stan Smith shoe and uses terms like 'adidas Originals' and 'Stan Smith' as keywords on its website to divert customers looking for authentic adidas shoes. We believe Skechers' unlawful behavior, which also includes misappropriation of Adidas' SUPERNOVA and Three-Stripe trademarks, needs to stop now."